1. Field of the Invention
The present invention generally relates to a broadcast receiver, a broadcast control method, and a computer readable recording medium. More specifically, the present invention is directed to a broadcast receiver and a broadcast control method, which are capable of effectively utilizing CM broadcasting time (commercial broadcasting time) within a broadcasting program, and also directed to a recording medium for recording thereon a computer readable program used to execute the broadcast control method.
2. Description of the Related Art
Very recently, various sorts of broadcasting networks appear in addition to the normally available television broadcasting system using the ground waves, known as cable television broadcasting systems and BS/CS satellite broadcasting systems using satellites. As a result, possibilities capable of selecting desirable programs are increased with respect to audiences. Also, the analog TV broadcasting systems such as the presently available ground wave TV broadcasting system will be replaced by the digital TV broadcasting systems such as the CS broadcasting system. Both the BS broadcasting systems and the ground wave broadcasting systems are to be replaced by the digital TV broadcasting systems in near future.
In near future, a watching style called a “time shift watching (listening/viewing) style” may be executed to constitute a general-purpose watching style, as large low cost capacities of random-accessible storage media (e.g., hard disks) are greatly realized and digital broadcasting systems substitute analog broadcasting systems.
The time shift watching style implies a style according to which random access media constituted in a logically-ring-shaped form are prepared as a buffer for temporarily storing reception data thereinto, and an audience watches a broadcast program while broadcast data received when the broadcast program is received is temporarily stored into the random access media. Since broadcast program data corresponding to the storage capacities of the random access media are saved therein, trick plays such as seek, pause, and replay operations may be realized at arbitrary timing within a watching broadcasting program by accessing this program data at random.
In receivers capable of realizing the time shift watching style, audiences may repeatedly view so-far-missed scenes. Also, even in such a case that a telephone call is made while an audience watches a broadcast program and/or a visiter suddenly comes so that the audience leaves from the present location to another location, if the present time is defined within a remaining storage capacity of random access media, then the audience may temporarily stop watching of the program, and after the audience finishes the subject matter, the audience again may restart watching of the interrupted program content.
Japanese Patent Application Laid-open No. Hei 6-14274 discloses the technique of the television receiver capable of realizing the time shift watching style, and also Japanese Patent Application Laid-open Hei 7-264529 describes the technique of such an apparatus capable of realizing the time shift watching style.
FIG. 38 is a diagram for representing a relationship between address positions and reproducing time of writing operation and reading operation with respect to a disk which is used as a buffer (will be referred to as a “buffer disk”) when the time shift watching style is performed.
Since a broadcast receiver receives broadcast data in a constant bit rate, a data writing rate with respect to a buffer disk is constant. As a result, as indicated by a dotted line in FIG. 38, a relationship between time and an address during writing operation becomes a straight line. Accordingly, since broadcast data is read out from the buffer disk at the same rate as the write rate, broadcast data can be reproduced in the normal speed. Symbols “t0” to “t2” shown in FIG. 38 correspond to broadcast data reproduction in the normal speed.
In such a case that an audience again wishes to watch a broadcast program from the beginning portion thereof at the time instant “t2” shown in FIG. 38, a position of an address “a0” is sought to set a read address. Thereafter, if the broadcast data is read at the normal speed rate, then the audience can again watch this broadcast program from the beginning portion thereof.
In such a case that the audience wants to reproduce the broadcast data in the fast forward mode in the time shift watching style, the read rate is set to become higher than the normal rate. This corresponds to the time instants “t2” to “t3” shown in FIG. 38. During the time period, the inclination of the straight line becomes larger than that when the reproduction is performed in the normal speed.
Symbols “t3” to “t6” shown in FIG. 38 represent that the broadcast data is reproduced under time shift condition and also in the normal speed. This is called an offset watching style. In this offset watching style, a straight line of a writing rate and also a straight line of a reading rate in FIG. 38 become in parallel to each other. In this case, a delay from the actual broadcasting time instant is equal to (t3−t1), since a scene which has been broadcasted at the time instant “t1” is watched at a time instant “t3”.
In the case of such a receiver which supports a reverse reproducing operation, when the broadcast data is reverse-reproduced, it becomes time instants “t6” to “t7” shown in FIG. 38. Since the broadcast data is read from the read address in the reverse direction, the read address is decreased while time has passed. The inclination of the straight line becomes a negative value.
When the audience pauses at a certain position while the broadcast data is reproduced, as shown in symbols “t7” to “t8” of FIG. 38, there is no change in the position of the read address a3, but only time is changed from the time instant “t7” to the time instant “t8.” Thereafter, in order to catch up the real-time broadcast program, the write address is made equal to the read address. In FIG. 38, at the time instant “t8”, the real-time broadcast program can be caught up. Subsequently, the audience can watch the program identical to the real-time broadcast.
Apparently, since future reception data which has not yet been stored cannot be read out from the buffer disk, a solid line which indicates a change in reading time cannot be located above a dotted line which represents a change in writing time.
As actions of audiences, a so-called “zapping action (zapping operation)” is usually carried out by these audiences. In this zapping action, when a commercial message (CM) program is commenced and this CM program has no direct relationship with a broadcast program which is being watched by an audience, this audience successively changes broadcast channels in order to seek other favorable programs. Various technical ideas capable of supporting this zapping action have been proposed.
Japanese Patent Application Laid-open No. Hei 5-316440 discloses the following technique of the TV receiver. That is, while the CM program contained in the broadcast program is detected from the speech control signal of the receiving broadcasting system, this TV receiver automatically switches this receiving broadcasting channel to other broadcasting channel, or a previously-registered specific channel. Furthermore, this patent application discloses such a technical idea that even after the present broadcasting channel has been changed into another broadcasting channel, the original broadcasting channel is kept under reception condition. At the time instant when the CM program of the original broadcasting program is ended, the television receiver is automatically returned to the original broadcasting channel.
As to such a technical point that another information is viewed during CM broadcasting, Japanese Patent Application Laid-open No. Hei 11-146296 discloses the technical idea capable of automatically displaying the image information such as the Internet home page while the CM program is detected. Also, this patent application describes that as the information provided instead of the CM program, the retrieved results obtained from the various sorts of information database which are stored in the CD-ROM and the like are exemplified in addition to the Internet home page.
In order to recognize a certain scene contained in a picture (video image) as a highlight scene, such a tag which may indicate “highlight scene” must be added. A tag may be realized by previously adding tag data when broadcast data is transmitted on the side of a transmission station. Alternatively, a tag may be added on the side of a receiver. There are two tag adding methods executed on the side of the receiver, namely a manual tag adding method and an automatic tag adding method. Since such a tag indicative of “highlight scene” is added to broadcast data, there are such merits that saved pictures may be simply retrieved, and contents of saved pictures may be grasped in short time.
Various retrieving methods have been proposed as to an automatic highlight scene retrieving method. For example, Japanese Patent Application Laid-open No. Hei 9-65287 discloses the technique of the featured scene listing method. That is, while the specific picture effect called a “desolve” contained in the broadcast program is sensed, the scene representative of the moving picture is specified.
However, the above-explained conventional techniques own the below-mentioned problems. That is, the audience is normally under relax condition while the audience watches the broadcast program at his home. Under such a circumstance, the audience never performs the time shift watching style unless there is such a specific reason that the program watching action by the audience is disturbed by the telephone call and/or the visitor. Also, in the conventional technique, the audience must issue such an instruction by himself, namely, a chance to replay a program watched in a real time mode in a half way.
The reasons why the zapping operation is carried out by audiences are mainly given as follows:
(1). In such a case that an audience does not have a clear decision on the next program after a presently watched broadcast program is ended, this audience owns a necessary and positive reason directed to a program search, namely the audience roughly checks all of presently watchable programs and then searches a favorable program.
(2). An audience owns such a passive reason: When the audience thinks a waste of time if the audience merely watches a CM program, this audience tries to search another channel program. Namely the presently watched CM program is replaced by the favorable broadcast program.
(3). An audience owns a positive reason without any necessity: Since this audience cannot be satisfied with the presently watched program, the audience tries to search the more enjoyable program.
(4). A reason is established by combining the above-explained reasons (1) to (3).
Generally speaking, such a zapping operation becomes effective in such a case that an audience can find out more favorable program in another channel, as compared with the presently watched program. However, there are many possibilities that while a CM program is broadcasted in a certain channel, CM programs are similarly broadcasted in other channel. Finally, since the audience could not find out his favorable program in another channel, this audience is returned to the originally watched program. Moreover, when the audience is returned to the original channel, there are many chances that the CM broadcast has already been accomplished, and therefore, this audience looses a head portion of a broadcast program after this CM broadcast is accomplished.
Also, since the zapping operation is required to perform the remote control many times, this remote control operation may cause very cumbersome operations for the audience. In the case that all of channels are not always free channels, but some channels are paid-channels, if an audience performs the zapping operation under careless condition, then the audience mistakenly watches such a paid-channel program, which may cause unnecessary expense.
When the conventional technique disclosed in Japanese Patent Application Laid-open No. Hei 5-316440 is used (namely, CM program is automatically detected to change present channel into another channel), the cumbersome manual operation required in the zapping operation can be eliminated. However, this conventional technique could not solve other difficulties. That is, the CM programs are similarly broadcasted in other channels, and/or no other favorable programs are broadcasted in other channels.
On the other hand, when the conventional technique disclosed in Japanese Patent Application Laid-open No. Hei 11-146296 is used (namely, other image information is displayed while CM program is broadcasted), the purpose for the CM program substitution (namely, audience watches information other than CM program) can be achieved. However, this conventional technique cannot meet such a requirement that the audience wishes to watch once again the highlight scene of the originally watched program by utilizing watching time for the CM program.
In general, a large number of CM programs are inserted into a time duration defined after a broadcast program is ended and before the next broadcast program is commenced. Also, spot news programs and weather forecast programs are inserted into this time duration. However, it is a waste of time when an audience watches the same news programs and weather forecast programs again which have been watched/known by this audience once already. As a consequence, the audience tries to change the presently watched channel to another channel. However, there are many occasions that news programs and/or weather forecast programs are similarly broadcasted in other channels at this channel change time. Therefore, the audience could not effectively utilize the time duration defined after one program is ended and before the next program is started, so that this audience may feel stress.
An object of the present invention is to provide a broadcast receiver, a broadcast control method, and also a recording medium for recording thereon a computer program, by which an audience can avoid loosing of his interests as to a content of a broadcast program even in a CM broadcasting time range contained in this broadcast program, while this audience no longer performs the zapping operation.